Ever increasing fuel costs continue to encourage rigid and semi-trailer tractor designers to search for additional, novel ways to improve vehicle fuel economy. Negative effects caused by air flow during travel are a frequent area of focus. Several measures have been taken by manufacturers to reduce aerodynamic drag by altering external shapes to minimize the restraining force that acts on any moving body in the direction of the freestream flow. Solutions such as fairings, deflectors, foils, sloping hoods, rolled-under bumpers, and recessed door handles can add design costs and weight, and complicate vehicle repair and servicing. Nevertheless, a designer's goal is to offset these negative effects with an overall reduction of the drag coefficient such that vehicle fuel economy can increase.
To continue to improve fuel economy, there remains a need to search for novel ways to minimize negative effects caused by air flow, while continuing to consider and offset negative impacts of such design changes and additional components.